Problem: $ { {-4} \times \left[\begin{array}{rr}{0} & {3} \\ {-1} & {-2} \\ {4} & {0}\end{array}\right] = {?} } $
To multiply a matrix by a number, multiply each item of the matrix by the number. ${\left[\begin{array}{rr}{-4}\times{0} & {-4}\times{3} \\ {-4}\times{-1} & {-4}\times{-2} \\ {-4}\times{4} & {-4}\times{0}\end{array}\right]}$ Now, simplify: ${\left[\begin{array}{rr}{0} & {-12} \\ {4} & {8} \\ {-16} & {0}\end{array}\right]}$